Sexual encounters between 4- and 5-year-old students were allegedly an "everyday thing" at a private California preschool that is closing its doors after coming under attack for a lack of supervision, the mother of a 5-year-old former student said.

Some students in the preschool class at the First Lutheran Church of Carson School in Carson, Calif., would engage in oral sex during nap time, in the tunnel slide on the playground and in an outside bathroom, attorney Greg Owen told ABCNews.com.

Owen had planned to file a lawsuit in Los Angeles County Superior Court on behalf of four students today, but he said he had decided to put that plan on hold as new students come forward.

"Their lives will be ruined in many ways," Owen said of the students. "And we know there are many more."

The California Department of Social Services cited the school, which is shutting down on Friday, for at least one of the sexual encounters, saying it had an improper student-teacher ratio.

Church administrators did not return multiple phone calls from ABCNews.com over the weekend and today. They told KABC last week that the school's closing was related to the director's resigning for personal reasons, and insisted the alleged sexual incidents had nothing to do with the closure.

Owen said there was a severe lack of supervision of the young students.

"There were times when teachers would let aides in the room for hours at a time to watch the kids," he said. "During nap time, the aides would be sleeping and the children would have been molesting each other during this time," he alleged.

The mother who spoke to KABC said her daughter had been caught by a teacher in the school bathroom performing oral sex on a 4-year-old boy.

"I said, 'Where did you see this? How did you know that this was something to do? 'She said, 'I saw another little girl do it.' I said, 'Well, where?' 'Here at school.' 'When?' 'During nap time,'" the mother said. She said her daughter switched schools in October.

Another parent told KABC that his 4-year-old son said he often received oral sex from a 5-year-old girl at school.

"He told me about all the bad things that girl had been doing to him," he said. "It went down in the classroom, it went down in the bathroom and it went down out on the playground."

With the mid-semester closing of the school, parents were scrambling to find alternatives but said it hadn't been easy.

"Parents are saying, 'My child is now a predator. Now how can I let him go to another school?" Owen said. "I have talked to three of the parents who have not been able to [find other schools], but I would think there are schools around.

"There were many children lying there, and they watched these acts. In our business and in psychological terms, that's sexualizing a child at a young age," he said.